The invention relates to a method for consolidating unconsolidated formations.
In the production of hydrocarbons from subterranean formations, unconsolidated formations are frequently encountered. Such formations must be consolidated in order to proceed with production of hydrocarbons from this formation, or particulate matter can enter the well.
If an unconsolidated formation is left unconsolidated, the flow of hydrocarbon and other subterranean fluids into a well will drag grains of sand and other debris from the formation into the well resulting in such debris being produced through various equipment. This debris is harmful and damaging to the equipment, and undesirable in the end product.
Currently, in order to address such problems, organic compounds and/or resins are disposed into the formation in a three-stage process. First, the resin is injected. Second, an activation system is injected for activating the resin. Third, a system must be injected for controlling permeability and dislodging excess resin.
The three-stage process itself is cumbersome and difficult to manage. In addition, the excess dislodging agents are difficult to control in order to avoid one of two extreme possible conditions, that is, high or low reactivity. High reactivity is undesirable in that weakness of consolidation can result, while low reactivity is undesirable in that the original formation permeability can be significantly reduced.
The three-system process also is disadvantageous in that management of more than one fluid during the process is required. This can cause difficulty in maintaining the sweeping efficiency of each fluid through the porous media. Further, these limitations are exacerbated in thick formations, and also in horizontal sections, where it is important to be sure that each subsequent fluid has the same sweep as the preceding fluid. Otherwise, some sections will not be treated to maintain permeability while other sections are not consolidated at all.
In light of the foregoing, it is clear that the need remains for a method for consolidating unconsolidated formations such as sand and the like.
It is therefore the primary object of the present invention to provide a method for consolidating unconsolidated formations.
It is a further object of the present invention to provide such a method wherein the steps required for completing consolidation are reduced.
Other objects and advantages of the present invention will appear hereinbelow.
In accordance with the present invention the foregoing objects and advantages have been readily attained.
According to the invention, a method for consolidating an unconsolidated formation is provided, which method comprises the steps of providing a well drilled to an unconsolidated formation; providing a consolidation fluid comprising a fluid suspension of nanoparticles; and flowing said consolidation fluid through said well and into said unconsolidated formation such that said nanoparticles establish stable bridges (bonds) between contacting grains of said unconsolidated formation.